what is the probability we will lose our status as world reserve currency and if that happens what currency will replace it?

The Euro has declared in 1989 to challenge the dollar as a world biggest reserve currency. But until today, it has never achieved its goal. The whole trade and investment is mostly intra the EU zone. So it is hard for third countries to get the Euro. The Yuan has been accepted by the IMF recently. But it lacks of international system to boost the Yuan status. The activities in Hong Kong and London are not enough. Now the Yuan has been used only bilateral trade organized by China. There is no currency to replace the dollar due to the lack of swap system the US has created and used as a sanction around the world. But the competition is there organized by Russia, India and China to trade with their local currencies and free from dollar.  It is working.

probably the Chinese Yuan 

The euro is also used around the world, But really, all the worlds currency can be exchanged. 

Not likely any time soon.

Renminbi.